Intermittent Fluoroscopy Research Articles

Retrospective case-control study on radiation dose for uterine artery embolization procedures.

Uterine artery embolization is performed in pre-menopausal women. Understanding the contribution of radiation dose at each stage of the procedure is important for potential dose reduction. The aim was to retrospectively analyse radiation dose on a per-procedural-stage basis, comparing digital subtraction angiography (DSA) and conventional roadmap (CRM). Group A consisted of 50 patients where DSA was used for road mapping at all stages: (I) Aortogram, (II) Left internal iliac artery (IIA) DSA, (III) Left uterine artery (UA) DSA, (IV) Right IIA DSA and (V) Right UA DSA. Group B included 50 patients, where CRM was used for road mapping at stages (II) and (IV). For Group A, mean total dose-area product (DAP) was 39.7 Gy·cm2; mean DAP for each stage were (I) Aortogram = 3.4 Gy·cm2, (II) Left IIA DSA = 5.9 Gy·cm2, (III) Left UA DSA = 3.2 Gy·cm2, (IV) Right IIA DSA = 5.5 Gy·cm2 and (V) Right UA DSA = 3.0 Gy·cm2. For Group B, mean total DAP was 33.6 Gy·cm2, mean DAP for each stage were (I) Aortogram = 3.3 Gy·cm2, (II) Left IIA CRM = 1.5 Gy·cm2, (III) Left UA DSA = 3.3 Gy·cm2, (IV) Right IIA CRM = 1.5 Gy·cm2 and (V) Right UA DSA = 3.3 Gy·cm2. Fluoroscopy time was 10 and 9.4 min for Groups A and B, respectively. The highest road-mapping radiation dose contribution was from bilateral IIA DSA. The use of CRM, intermittent fluoroscopy and elimination of the aortogram is recommended to further reduce procedural radiation dose.

Current state of awareness and safety practices for ionising radiation risks in orthopaedic doctors in Navi Mumbai: an online survey

Background: Radiographic imaging in orthopaedic surgical centers is becoming more common, posing additional risks to the orthopaedic doctors, who become more exposed to ionising irradiation. As a result, orthopaedic surgeons must have a good understanding of radiation hazards. Despite these issues, many orthopaedic specialists do not get basic radiation safety training. A review of orthopaedic specialists' understanding, awareness, and routine radiation safety practices at an academic hospital in Navi Mumbai. Methods: After institutional ethical approval, a panel of experts created an online survey comprising multiple-choice questions, which was utilized to perform a descriptive research. The questionnaire contained several aspects, each of which assessed orthopaedic understanding, awareness, and practices. The research cohort comprised orthopaedic doctors working through our tertiary medical center and medical college. Results: According to our findings, only 82% of respondents were aware of the radiation dangers associated with fluoroscopy. The use of lead aprons, thyroid shields, goggles, and protective caps is 99%, 42%, 25%, and 25%, respectively. Despite the fact that 60% of respondents were aware of TLD badges. Only 23% of those who operate with inosing radiation use TLD badges. Approximately 61% of respondents were ignorant of intermittent fluoroscopy, and 85% utilized the C-arm tube while the device was active. Conclusions: The vast majority of orthopaedic doctors utilise fluoroscopic imagery in the operating room on a daily basis, but they lack in-depth information and awareness about the radiation security hazards connected with this imaging modality. It is consequently advised that a radiation safety training curriculum be implemented.

Insights into handling and delivery of Y-90 radioembolization therapies.

The use of Y-90 radioembolization techniques has become a standard tool for the treatment of liver cancer and metastatic diseases that result in liver lesions. As there are only two approved forms of radioembolization therapy, the procedures for use are also fairly standardized even though exact international and interdepartmental procedures can vary. What has been less published over the years are the nuanced differences in delivery techniques and handling of the two available Y90 radioembolization therapies. This paper seeks to examine various aspects of delivery techniques, product handling, and radiation exposure that differ between the available and approved products. Understanding these differences can assist with providing more efficient treatment, confirmation of accurate therapy, more informed handling of the products, and improved training of physicians and other hospital staff. Two commercially available and approved radioembolization devices were compared to assess nuanced, but key differences between the available products regarding therapy delivery, handling of the products, and radiation exposure to patients and staff. This work is broken into two sections: (1) Therapy Delivery, (2) Radiation Safety. Therapy delivery characteristics were assessed by using an external radiation detector system with detectors placed inside of each delivery system facing the dose vial and on the output catheter lines to the patient. Additional detectors were placed near the liver of the patient and on top of the foot to measure extremities. Data were acquired continuously throughout therapy delivery to collect time activity curves (TACs) for the characterization of each therapy. These data were analyzed to assess if (a) real-time monitoring of radiation could be used to provide an accurate assessment of residual dose before the patient leaves the procedure room, and (b) can dose delivery characteristics be observed that enable improved training and quality control. Calculation of residual dose using the external detector TACs was performed by analyzing initial and final activity peaks to determine measured count rate differences. Radiation safety aspects were assessed by monitoring radiation exposure to staff handling each of the available therapy products. Nuclear medicine technologists and interventional radiology physician body and hand doses were measured for each delivered therapy using standard body and ring dosimeters. The TACs noted above collected for the liver and extremities were used to assess if any off-target or leached Y90 activity could be detected for each therapy. Blood was collected at times before, during, and after treatment and then counted on a gamma counter to assess differences in free Y90 circulating in the blood. Each patient in this study also received a post-treatment whole-body PET/CT at 2-4 h post-infusion to assess for any aggregate free Y90 deposition that may have resulted from circulating free Y90 in the subject following therapy. Calculations of residual dose in the vial following therapy using the real-time detection methods resulted in values that were not statistically different from the values calculated by nuclear medicine following the procedure ( ). Real-time collection of dose delivery data enabled observation of key characteristics related to each delivery method. For SIR-spheres procedures, the cycle of pushing the dose and visualizing with fluoro can easily be seen with each push resulting in a smaller and smaller peak with intermittent fluoroscopy pulses. TheraSpheres infusions show a rapid bolus with nearly all of the measurable injected activity being infused in the first push of the dose. Staff radiation exposure assessments showed statistically significant differences between glass and resin spheres for hand doses of physicians and technologists (p > 0.05), but no statistical difference between body doses for both products ( ). Assessments of free Y90 circulating during therapy showed that patients undergoing therapies with resin spheres had post-infusion blood levels that were 120% higher than pre-infusion levels while glass sphere therapy patients only saw a 7% rise in post-infusion blood levels. The coefficients of variation (COVs) across glass sphere measurements pre, during, and post, were only 0.008 while resin sphere measures saw much greater variability with a COV of 0.45. Both glass and resin therapies showed blood levels at 2-4 h post-injection to be similar to levels measured pre-injection. Neither therapy showed any signs of focal aggregation at 2-4 h post-infusion on whole-body PET/CT. Although glass and resin radioembolization therapies are similar, they both have unique characteristics related to their administration and handling by staff. Understanding the nuances can assist in providing more efficient delivery, better staff education, and reducing radiation exposure to everyone involved with these therapies. The use of near real-time monitoring is feasible and can be used to obtain critical information about the delivery success of a therapy and can inform physicians on their techniques to optimize their practice as well as provide more consistent training to residents.

Helical CT versus intermittent CT fluoroscopic guidance for musculoskeletal needle biopsies: impact on radiation exposure, procedure time, diagnostic yield, and adverse events.

Image-guided percutaneous needle biopsies are essential in the workup of musculoskeletal (MSK) lesions. While helical CT (HCT) is well established, intermittent CT fluoroscopy (iCTF) is an increasingly used alternative. The purpose of this study is to establish whether differences in subject radiation exposure, procedure time, yield, or adverse events exist between HCT and iCTF guidance. This retrospective cohort study included consecutive MSK needle biopsies performed on a single-CT scanner over a 12-month period at a tertiary academic center. Subject demographics, radiation dose, and outcomes were abstracted from the medical record. Comparisons between the two cohorts were performed using Student's t-test for continuous data and using Fisher's exact test for categorical data and a two-tailed p value less than 0.05 was considered significant. Two hundred sixteen adults (115 (53.2%) females) with a mean age of 58.8 ± 18.4years, underwent 216 biopsies (109 (50.5%) HCT guided, 107 (49.5%) iCTF guided) between June 2017 and June 2018. Dose-length product (DLP) and volume CT dose index (CTDIvol) were significantly higher for the HCT cohort (HCT 698.9 ± 400.8 mGycm vs iCTF 312.8 ± 170.8 mGycm; p < 0.005 and HCT 19.1mGy ± 8.8 vs iCTF 6.9mGy ± 1.5, p < 0.001). No significant difference in diagnostic yield, procedure time, or adverse event rate was identified. For CT-guided MSK needle biopsies, iCTF decreases subject radiation dose compared to HCT without negatively affecting outcomes. iCTF should be strongly considered by radiologists performing MSK biopsies given the reduced patient radiation exposure.

Contrast Medium Volume Needed to Reach Anterior Epidural Space via the Kambin Triangle or Subpedicular Approach for Transforaminal Epidural Injection

Transforaminal (TF) lumbar injection is a commonly used minimally invasive intervention for management of chronic low back pain. TF injection can be performed using various approaches to inject the drug to the anterior epidural space (AES). To identify the volumes of contrast medium needed to reach the AES and other landmarks in the Kambin triangle (KB) and subpedicular (SP) approach of TF injection in patients with lumbosacral radicular pain. Randomized controlled trial. Pain clinic and operating room of a tertiary care hospital. Seventy-five eligible patients were randomized to receive TF epidural injection either by SP (SP group; n = 38) or the KB (KB group; n = 37) approach under fluoroscopic guidance. After confirming the appropriate needle position, contrast medium was injected at 0.5 mL increments up to 2 mL under intermittent fluoroscopy. Contrast medium volumes needed to reach specific landmarks, that is, AES, medial to superior pedicle, medial to inferior pedicle, medial aspect of both the superior, and neural spread, were recorded. Following this, 4 mL of the drug (0.5% lidocaine 1 mL + methylprednisolone 80 mg + 1 mL normal saline solution) was injected. Patients were evaluated for Visual Analog Scale (VAS) and modified Oswestry Disability Questionnaire (MODQ) scores after epidural injections at 2 weeks, 1 month, and 2 months. Average volume of contrast medium needed to reach AES was 1.10 ± 0.46 mL in the KB approach and 1.10 ± 0.38 mL in the SP approach. Contrast medium volume needed to reach other landmarks showed comparable results in both groups. AES was seen in 27.02% (10/37) patients in the KB group and 23.6% (9/38) patients in the SP group with 0.5 mL of contrast medium. This increased to 56.76% (21/37) and 77.7% (28/38) with 1 mL of contrast medium (P = 0.03, chi-square test). No anterior spread was seen even after 2 mL of contrast medium in 4 patients in the KB group and 2 patients in the SP group. Neural spread was seen in 100% of patients in the KB group after 0.5 mL of contrast medium, but in 34 (89.4%) patients in the SP group (P = 0.03, chi-square test). We did not note any contralateral spread. Short-term effectiveness in pain relief in terms of VAS for back pain and functional improvement in terms of MODQ score over time showed similar results in both groups. Intravascular needle puncture and needle paresthesia was comparable in both groups. Small follow-up duration is one the limitations of this study. Future studies will be needed to assess any long-term differences in outcome between approach methods. Also, use of intermittent fluoroscopy might have limited detection of intravascular injections of the contrast medium in comparison to the continuous fluoroscopy. To conclude, our study revealed that average volume of contrast medium needed to reach AES and other landmarks were comparable with both approaches of TF injection. Transforaminal injection, subpedicular approach, Kambin triangle approach, contrast medium spread, anterior epidural spread.

Low incidence of vascular uptake during ganglion impar sympathetic nerve blocks for coccydynia.

Context:Focal sympathetic nerve blocks of the ganglion impar are often effective treatments for coccydynia (coccyx pain) and other pelvic pain syndromes. These injections are generally performed under contrast-enhanced fluoroscopic guidance. Vascular uptake may potentially occur during the injection and vascular uptake rates have been reported for other spinal injections, but never for ganglion impar blocks. Aims:The purpose of the study was to determine vascular uptake rates during fluoroscopy-guided ganglion impar blocks. Settings and Design:An academic/University-based Coccyx Pain Center. Methods and Materials:A total of 78 consecutive trans-coccygeal ganglion impar blocks were analyzed for vascular uptake of contrast as determined by intermittent fluoroscopy. Statistical Analysis Used:Direct calculation of incidence. Results:Only one patient (1.3%) demonstrated a vascular uptake pattern, which was readily recognized and corrected by slightly adjusting the position of the needle tip and thereby subsequently obtaining the desired contrast pattern at the ganglion impar. Conclusions:Vascular uptake incidence is low during ganglion impar blocks. This information can be one of the multiple factors considered when a physician is deciding whether or not to use contrast in an individual patient.

Description of a novel method for renal puncture in supine percutaneous nephrolithotomy and comparison with a previously described method.

The supine position is becoming increasingly popular in percutaneous nephrolithotomy (PNL). Renal puncture is the key step for a successful PNL procedure. The aim of this study was to describe a novel method for renal puncture and compare it with a previously described method. Data of 358 patients who underwent PNL in the supine position were collected prospectively. In 165 patients, the puncture was performed by a previously described method (Group 1), and in 193 patients, the puncture was performed with the novel method (Group 2). Groups were compared with regard to total time and fluoroscopy time to successful puncture. In the novel puncture technique, the needle is advanced toward the targeted calyx under monoplane fluoroscopy. To determine the needle depth, the C-arm is rotated by 10°. If the needle projection is beyond the targeted calyx in fluoroscopy, the puncture is deeper than desired. If the needle projection does not reach the targeted calyx, the puncture is more superficial than desired. Groups were similar with regard to the mean age, gender distribution, body mass index, stone size, and site of puncture. The mean total time to puncture was 88.2±25.3 seconds in Group 1 and 54.3±22.3 seconds in Group 2, and the difference was statistically significant (p=0.03). The mean fluoroscopy time to puncture was 16.1±5.3 seconds in Group 1 and 9.3±3.4 seconds in Group 2, and the difference was statistically significant (p=0.03). This novel method to determine the depth of the needle is simple, reproducible, and has the potential to diminish radiation exposure with the aid of intermittent fluoroscopy.

CT Fluoroscopy-Guided Drain Placement to Treat Infected Gastric Leakage after Sleeve Gastrectomy: Technical and Clinical Outcome of31 Procedures.

To observe the technical and clinical outcome as well as safety of CT fluoroscopy-guided drain placement in the multimodal clinical complication management of superinfected gastric leakage after sleeve gastrectomy. All consecutive patients who underwent CT fluoroscopy-guided drain placement to treat superinfected postoperative leakage after sleeve gastrectomy in our department between 2007 and 2014 were included in this retrospective study. All interventions were performed on a 16- or 128-row CT scanner under intermittent CT fluoroscopy guidance (15-25 mAs, 120 kV). The technical and clinical success rates as well as complications, additional therapies and patient radiation dose were analyzed. 14 patients (mean age: 43.8 ± 11.3 years, mean BMI: 52.9 ± 13.5, 7 women) who underwent a total of 31 CT fluoroscopy-guided drain placement procedures were included. 30 of 31 interventions (96.8 %) were technically successful. 7patients underwent more than one intervention due to drain obstruction or secondary dislocation or as further treatment. During and after the intervention no procedure-associated complications occurred. In all patients, inflammation parameters decreased within days after the CT-guided intervention. The total interventional dose length product (DLP) was 1561 ± 1035 mGy*cm. CT fluoroscopy-guided drain placement has been shown to be a safe minimally invasive procedure that rarely leads to complications for treating superinfected gastric leakage occurring after sleeve gastrectomy. We assume that operative revisions in a high-risk patient group can be avoided using this procedure. · CT fluoroscopy-guided drain placement in obese - often medically highly complex - patients is a technically feasible procedure.. · Multimodal treatment (CT intervention, endoscopy and surgery) is required to successfully treat gastric leakage after bariatric surgery.. · High-risk surgery might be avoided by the CT-guided drain placement.. · Schwarz J, Strobl FF, Paprottka PM et al. CT Fluoroscopy-Guided Drain Placement to Treat Infected Gastric Leakage after Sleeve Gastrectomy: Technical and Clinical Outcome of 31 Procedures. Fortschr Röntgenstr 2020; 192: 163 - 170.

Intermittent CT fluoroscopic guided lung biopsy - Retrospective analysis of success rate, radiation exposure, complications and duration of procedure.

Intermittent CT fluoroscopic biopsy is a new technology, but has not been studied widely. This study aims to investigate correlation between the radiation dose and fluoroscopic CT exposure factors to establish the low dose parameters for performing percutaneous lung biopsies, as well as the relationship of the mean diameter and depth of lesions with radiation dose, procedure time, success and complication rates. This is a retrospective study to analyse lung biopsies performed using intermittent CT fluoroscopic technique with 18 G semi-automated coaxial gun on 256 slice scanner. A total of 50 patients were included in the study. Biopsy was done in three mAs and KVp settings (30 and 70, 10 and 120, 30 and 120, respectively). The statistical data analysis was performed using SPSS Statistics software. Pneumothorax occurred in 22 % of cases. Sampling rate was 98% but histopathological diagnosis was made in 94% cases. Mean procedure time was 30.5±11.1 minutes. Low dose protocol (30 mAs and 70 KVp) had least radiation exposure during biopsy procedure (p < 0.001) with similar success rate, complications and procedure time (p > 0.05) in comparison with high dose protocol (10 and 120, 30 and 120 mAs and KVp, respectively). Mean diameter of lesions didn't correlate with radiation dose, success rate, complications and duration of procedure (p > 0.05) while significant association was found when depth was correlated with radiation exposure during fluoroscopic biopsy, duration of procedure and complication rates (p < 0.05) while no association was found with success rates. On third generation dual energy source CT scanner, reducing mAs and KVp to 30 and 70 during fluoroscopy biopsy can produce images whose complications and success rates are comparable to high dose CT. In general, intermittent CT fluoroscopy guided lung biopsy has good success rates with acceptable complications, while utilising less radiation dose and procedure time.

Periradicular Infiltration of the Cervical Spine: How New CT ScannerTechniques and Protocol Modifications Contribute to the Achievement of Low-Dose Interventions.

CT-guided periradicular infiltration of the cervical spine is an effective symptomatic treatment in patients with radiculopathy-associated pain syndromes. This study evaluates the robustness and safety of a low-dose protocol on aCT scanner with iterative reconstruction software. A total of 183 patients who underwent periradicular infiltration therapy of the cervical spine were included in this study. 82 interventions were performed on a new CT scanner with a new intervention protocol using an iterative reconstruction algorithm. Spot scanning was implemented for planning and a basic low-dose setup of 80 kVp and 5 mAs was established during intermittent fluoroscopy. The comparison group included 101 prior interventions on a scanner without iterative reconstruction. The dose-length product (DLP), number of acquisitions, pain reduction on a numeric analog scale, and protocol changes to achieve a safe intervention were recorded. The median DLP for the whole intervention was 24.3 mGy*cm in the comparison group and 1.8 mGy*cm in the study group. The median pain reduction was -3 in the study group and -2 in the comparison group. A 5 mAs increase in the tube current-time product was required in 5 patients of the study group. Implementation of a new scanner and intervention protocol resulted in a 92.6 % dose reduction without a compromise in safety and pain relief. The dose needed here is more than 75 % lower than doses used for similar interventions in published studies. An increase of the tube current-time product was needed in only 6 % of interventions. · The presented ultra-low-dose protocol allows for a significant dose reduction without compromising outcome.. · The protocol includes spot scanning for planning purposes and a basic setup of 80 kVp and 5 mAs.. · The iterative reconstruction algorithm is activated during fluoroscopy.. · Elsholtz FH, Kamp JE, Vahldiek JL et al. Periradicular Infiltration of the Cervical Spine: How New CT Scanner Techniques and Protocol Modifications Contribute to theAchievement of Low-Dose Interventions. Fortschr Röntgenstr 2019; 191: 54 - 61.

Evaluation of surface dose and image quality using the half-scan mode in chest computed tomography-guided interventional radiology: a phantom study.

The authors aimed to evaluate the effects of the half-scan mode on image quality and physician exposure to radiation in computed tomography (CT)-guided interventional radiology (IVR) to the right lung using an intermittent CT fluoroscopy technique for measuring phantom surface dose distribution and image noise. For the half-scan mode, settings at 0°, 90°, 180°, and 270° were used as the central axis of the X-ray exposure range on the chest phantom. With the center of the ventral side in the chest phantom defined as 0°, optically stimulated luminescent dosimeters were attached at five positions at 30° intervals on the right side of the phantom surface. Securing a space for device operation during the procedure is necessary. The couch was shifted downward by 50mm to reproduce the conditions used for measurement in clinical settings. Image noise and contrast-to-noise ratio were measured to assess image quality; subjective evaluation was performed using simulated lung nodules placed in the phantom. The phantom surface dose distribution in the measured half-scan mode depended on the angle setting. Additionally, the phantom surface dose in the half-scan mode at the 90° setting was reduced by approximately 50%; however, image quality was clearly decreased. In CT-guided IVR to the right lung, using a lead drape and half-scan mode according to the procedural situation is important.

Periradicular infiltration of the lumbar spine: testing the robustness of an interventional ultra-low-dose protocol at different body mass index levels.

Background Computed tomography (CT)-guided periradicular infiltration remains a frequent interventional procedure for treatment of low back pain. Purpose To present an interventional ultra-low-dose protocol for CT-guided periradicular infiltration therapy and assess its application at different body mass index (BMI) levels. Material and Methods Over a period of 14 months, 79 patients underwent 183 CT-guided interventions for single-site lumbar periradicular therapy using an ultra-low-dose protocol with a basic setup of 100 kV and 5 mAs. Procedures were performed via intermittent fluoroscopy. A retrospective review was performed to analyze the parameters tube current and tube voltage, dose-length product, and BMI. Results The interventional ultra-low-dose protocol allowed safe treatment of 91.1% of the patients without a need for adapting the protocol. In seven patients with a higher BMI (range, 31-38 kg/m2; mean, 34 kg/m2), the tube current had to be increased to retain sufficient image quality. Only patients with a BMI of 30 and higher showed a significant correlation between BMI and dose-length product ( P value = 0.02), resulting in a slightly increased dose ( P value = 0.002). Conclusion The protocol presented for the interventional part of CT-guided periradicular infiltration allows to safely treat patients with a median calculated effective dose of 0.045 mSv (converted from a dose-length-product of 2.26 mGy*cm). Patients with a BMI of 30 and higher required a higher calculated effective dose with just one patient slightly exceeding 0.1 mSv.

Lumbar Epidural Steroid Injections.

Lumbar radiculopathy is a common diagnosis for patients who present with low-back pain and leg pain, typically along a particular dermatome. This pain is commonly associated with a lumbar disc herniation. The prognosis is usually favorable, and the symptoms can resolve spontaneously over time. In patients in whom leg and back symptoms are severe, lumbar epidural (cortico)steroid injections are good options for the short to medium-term management of pain. Currently, lumbar epidural steroid injections are performed with radiographic guidance systems and fluoroscopy. This method is preferred because of the increased accuracy in needle placement and the reduced risk of injury to nerves and vascular structures. The procedure is performed with the following steps: (1) Following appropriate patient selection through clinical evaluation and assessment of imaging studies such as computed tomography or magnetic resonance imaging, the patient is prepared and draped after providing written informed consent. (2) The level of neural compression to be injected is identified with intermittent fluoroscopy and the use of a radiopaque marker. (3) The skin and subcutaneous tissues are anesthetized. (4) A spinal needle (Quincke or Tuohy type) is inserted after tissues are fully anesthetized. The needle is slowly advanced with the use of intermittent fluoroscopy until the target is reached. In the case of an interlaminar approach, this would be associated with a loss of syringe resistance and piercing of the ligamentum flavum. In the case of a transforaminal approach, this would be associated with the 6 o'clock position of the pedicle on the side in question. (5) Contrast material is then injected with the use of live fluoroscopy to confirm appropriate placement and exclude intravascular and intrathecal injection. (6) When adequate placement is confirmed, a solution of steroid and anesthetic is administered. The needle is then removed. Most outcome reports after lumbar epidural steroid injections are favorable for radicular symptoms. Associated back pain may typically improve as well. Common complications include injection site pain or soreness, infections, allergy, and inadvertent dural puncture with spinal headache.

CT fluoroscopy-guided closed-tip catheter placement before regional hyperthermia treatment of soft tissue sarcomas: 5-Year experience in 35 consecutive patients

Purpose: This study was designed to assess technical success and complications in patients with high-risk soft tissue sarcomas undergoing CT fluoroscopy-guided closed-tip catheter placement before treatment with combined chemotherapy and regional hyperthermia. Materials and methods: This retrospective study comprised all patients referred for insertion of closed-tip catheters for the introduction of thermometry probes before regional hyperthermia treatment at a single university centre from 2010 to 2015. Catheter placements were performed under local anaesthesia and intermittent CT fluoroscopy guidance. Technical success, complication rate, duration of catheter insertion and dose–length product (DLP) were analysed. Technical success was defined as intratumoural catheter placement suitable for subsequent thermometry. Results: A total of 35 procedures were performed on 35 patients (22 men, 13 women). In 34 out of 35 interventions catheters were inserted successfully; in one patient catheter placement was not feasible. No intra-interventional complications occurred. In six patients post-interventional complications were observed – two major (one abscess formation and one severe catheter dislocation) and four minor complications. Technical failure was observed in 11.4% of patients, especially catheter kinking. A total of 55 catheters were placed, with a mean number of 1.7 ± 0.7 per patient. Mean total DLP was 723.2 ± 355.9 mGy*cm. Conclusion: CT fluoroscopy-guided closed-tip catheter placement into high-risk soft tissue sarcomas was characterised by high technical success and relatively low complication rate. While major complications were rarely observed, catheter-kinking preventing successful thermometry represented the most frequent technical failure.

Radiofrequency Ablation of Hepatocellular Carcinoma Located in the Liver Dome Under Intermittent CT Fluoroscopy Guidance

Purpose: To evaluate the clinical effectiveness of an intermittent computed tomography (CT) fluoroscopy-guided radiofrequency (RF) ablation of hepatocellular carcinoma located in the liver dome. Materials and Methods: Between 2005 and 2010 23 patients with hepatocellular carcinoma (HCC) nodules located in the liver dome underwent an intermittent CT fluoroscopy-guided RF ablation. The primary endpoint was the local tumor progression. Procedure-related complications occurred in 3 of 23 patients. To evaluate the prognostic factors for the local tumor progression, univariate and multivariate analyses were performed using the Cox proportional hazards model. The chisquared test was performed to evaluate the association of access route and procedure-related complication. The study was approved by the Institutional Review Board of our hospital. Results: The Tumor sizes ranged between 1.0 and 2.9 cm. An initial complete ablation was achieved in all patients. The median follow-up period was 31 months and the major complication rate was 4.3%. The cumulative rate of local tumor progression at 3 years was 20%. The univariate analysis revealed that only serum total bilirubin level (p = 0.048) and prior chemoembolization were statistically significant (p = 0.044), but there was no independently significant prognostic factor on multivariate analysis. Procedure-related complications occurred in 3 of 23 patients. Conclusion: For HCC located in the liver dome an intermittent CT fluoroscopyguided RF ablation could be performed safely and effectively. Index terms

Incidence of Pulmonary Cement Embolism after Real-Time CT Fluoroscopy–guided Vertebroplasty

PurposeTo prospectively evaluate the incidence of pulmonary cement embolism (PCE) after vertebroplasty in procedures performed under real-time computed tomographic (CT) fluoroscopy guidance. Materials and MethodsA total of 85 vertebroplasties were performed in 51 consecutive patients (31 women, 20 men; mean age, 71.9 y; range, 48–92 y) in 51 sessions. The needle was inserted with guidance from intermittent single-shot CT scans, and intermittent CT fluoroscopy was used during cement injection only. To reduce the risk of extravertebral or extraosseous leakage, several procedures (cement injection stopping/slowing, needle position changes) were employed. The chest and treated bone were scanned immediately after vertebroplasty. These CT images included the entire thorax as well as the treated vertebrae. ResultsNo cement emboli were observed on CT after vertebroplasty. After 85 vertebroplasty procedures, 44 extravertebral leaks were detected. Epidural leaks were observed on CT in six treated vertebrae (7%), in 12 cases in the anterior external venous plexus (14.1%), in five in the azygos vein (5.8%), in 19 in the disc space (22%), and in two in the foraminal space (2.3%). On a per-patient basis, the odds of leaks increased with the number of vertebroplasties (P = .05) and the volume of cement used (P = .0412). There was also a higher probability of leak (P < .05) for osteoporotic vertebral compression fractures (67.9%; 95% confidence interval, 47.7%–84.1%) than osteolytic spinal metastases (34.8%; 16.4%–57.3%). ConclusionsPCE did not occur after vertebroplasty under CT fluoroscopy guidance. Further larger prospective vertebroplasty studies are needed to compare the rates of PCE for CT versus conventional fluoroscopic guidance.

CT-guided nerve block: a review of the features of CT fluoroscopic guidance for nerve blocks

Nerve blocks are an attractive interventional therapy in pain medicine. Several image guidance methods are available to secure the safety, accuracy, and selectivity of the nerve block. Computed tomography (CT) guidance provides a clear view of the vital viscera and vessels that should be avoided by the needle, and accurate placement of the needle tip before neuro-destructive procedures. A recent advance in CT technology is multi-slice CT fluoroscopy, which allows for rapid and easy correction of needle tip placement during insertion. To reduce the radiation dose for both patients and staff, the lowest radiation setting, intermittent quick-check fluoroscopy, and shortening of the planning scan should be used. Preliminary CT scanning with excellent spatial resolution may facilitate the application of CT fluoroscopic guidance to various types of nerve blocks. Here we review celiac plexus and splanchnic nerve blocks, trigeminal nerve block, neurolytic sympathectomy, and spinal intervention performed under CT guidance. Additional large-scale studies are needed to optimize the use of image guidance, especially CT fluoroscopy guidance, for nerve blocks.

Sacroplasty for Symptomatic Sacral Hemangioma: A Novel Treatment Approach

Painful vertebral body hemangiomas have been successfully treated with vertebroplasty and kyphoplasty. Sacral hemangiomas are uncommon and as such painful sacral hemangiomas are rare entities. We report what we believe is only the second successful treatment of a painful sacral hemangioma with CT-guided sacroplasty. A 56-year-old woman with a history of right-sided total hip arthroplasty and lipoma excision presented to her orthopedic surgeon with persistent right-sided low back pain which radiated into her buttock and right groin and hindered her ability to walk and perform her activities of daily living. MRIs of the thoracic spine, lumbar spine and pelvis showed numerous lesions with imaging characteristics consistent with multiple hemangiomas including a 2.2×2.1 cm lesion involving the right sacrum adjacent to the right S1 neural foramen. Conservative measures including rest, physical therapy, oral analgesics and right-sided sacroiliac joint steroid injection did not provide significant relief. Given her lack of improvement and the fact that her pain localized to the right sacrum, the patient underwent CT-guided sacroplasty for treatment of a painful right sacral hemangioma. Under CT fluoroscopic guidance, a 10 gauge introducer needle was advanced through the soft tissues of the back to the margin of the lesion. Biopsy was then performed and after appropriate preparation, cement was then introduced through the needle using a separate cement filler cannula. Appropriate filling of the right sacral hemangioma was visualized using intermittent CT fluoroscopy. After injection of approximately 2.5 cc of cement, it was felt that there was near complete filling of the right sacral hemangioma. With satisfactory achievement of cement filling, the procedure was terminated. Pathology from biopsy taken at the time of the procedure was consistent with hemangioma. Image-guided sacroplasty with well-defined endpoints is an effective, minimally invasive and safe procedure. Patients with painful sacral hemangiomas can be treated with this technique with no significant complications.

Cervical Medial Branch Block

Cervical medial branch blocks are commonly performed for the diagnosis and treatment of head, neck, and shoulder pain. Intermittent fluoroscopy is widely used for needle positioning and visualization of contrast distribution before medication injection. The purpose of this study was to examine the use of ultrasound as an alternative imaging technique to block the third occipital nerve and the C3 to C6 medial branches. The study involved 2 phases with a total of 53 patients. The purpose of phase 1 was to assess the reliability of needle positioning using an ultrasound target corresponding to the middle of the bony contour of the articular pillar. Twenty patients undergoing 46 cervical medial branch blocks between C3 and C6 were recruited, and the needle tip position was graded on a 3-point scale based on its proximity to the centroid on lateral radiograph. In phase 2, 50 patients undergoing 163 levels were recruited. Using ultrasound guidance, each of the targeted levels was injected with 0.3 mL of a 1:1 mixture of local anesthetic and contrast agent. A blinded assessor reviewed contrast distribution in the anteroposterior and lateral radiograph views. In phase 1, all needle tips were positioned on the articular pillars; furthermore, 80.1% were located in the middle 2 quarters of the latter. In phase 2, the contrast was found to cover the appropriate level in 94.5% of cases, and no complications were noted. The incidence of aberrant spread to adjacent levels (13.5%) was similar to that reported with fluoroscopy. Ultrasound guidance offers a reliable alternative to fluoroscopy for third occipital nerve and C3-C6 cervical medial branch blocks. Further studies are required to validate the clinical efficacy of our technique.

Technical note: Reduction of radiation dose using ultrasound guidance during transjugular intrahepatic portosystemic shunt procedure

The transjugular intrahepatic portosystemic shunt (TIPS) procedure for decompression of the portal venous system generally performed under fluoroscopic guidance has undergone continuous technical modifications recently. Due to the length of the procedure, the fluoroscopy times are reasonably high, thus increasing the risk from ionizing radiation. Radiation doses were measured for 19 patients using dose area product (DAP) meter. The average DAP value for the TIPS procedure was 63.86 Gy cm2 (21.12-117.07). Radiation doses to patients can be reduced with the use of USG guidance and intermittent fluoroscopy screening.